getOpcRetryToken

A token that uniquely identifies a request so it can be retried in case of a timeout or server error without risk of executing that same action again. Retry tokens expire after 24 hours, but can be invalidated before then due to conflicting operations Example: If a resource has been deleted and purged from the system, then a retry of the original delete request may be rejected.

getIfMatch

For optimistic concurrency control. In the PUT or DELETE call for a resource, set the if-match parameter to the value of the etag from a previous GET or POST response for that resource. The resource will be updated or deleted only if the etag provided matches the resource’s current etag value.